Simple seafood chowder

Name: Simple seafood chowder
Ingredients: 1 tbsp vegetable oil; 1 large onion chopped; 100g streaky bacon chopped; 1 tbsp plain flour; 600ml fish stock made from 1 fish stock cube; 225g new potato halved; pinch mace; pinch cayenne pepper; 300ml milk; 320g pack fish pie mix (salmon, haddock and smoked haddock); 4 tbsp single cream; 250g pack cooked mixed shellfish; small bunch parsley chopped; crusty bread to serve